DENVER — In keeping with a recent trend that has the Astros if not optimistic at least encouraged, Thursday’s series finale against the Colorado Rockies had two unlikely candidates carry the team offensively.

The duo, the seventh and eighth batters in the order, singlehandedly managed to keep the offense hot, combining for five RBIs and all of the team’s hits to fuel the Astros to a 5-4 victory before 28,329 at Coors Field.

Aside from clinching them the four-game series, the win was the Astros’ third straight and eighth in 10 games.

And it made a winner out of Roy Oswalt, who tied his season-high for strikeouts with nine while allowing just two runs on four hits over seven innings to snap a two-game losing streak.

“You’re bound to have good days,” Quintero said. “Carlos (Lee) had a big game yesterday; today it was Manzella and me. Tomorrow maybe it’s another guy. It’s what we have to do to win these games.”

For Astros manager Brad Mills, there was no secret to the team’s newfound success.

“We’ve been playing more consistent,” Mills said. “Everybody’s starting to pitch in and do a little bit here and there on both sides of the ball. And then we’re getting the work from our pitching, both our starters and relievers.”

Still, the Rockies (30-30) made sure the latest successful result did not come easy.

Key out from Daigle

The Astros (25-36), who entered the bottom of the eighth with a three-run lead, quickly found themselves hanging on tight after Colorado rallied for two runs off reliever Wilton Lopez.

But that was before righthander Casey Daigle got pinch-hitter Jason Giambi to pop out for the final out of the inning with the tying run at third base.

Reliever Brandon Lyon pitched a 1-2-3 ninth for his first save of the season.

“What a nice game to get, having to piece it together a little bit,” Mills said. “Roy did a great job giving us another quality start, and I can’t say enough about ‘Q’ and Manzella getting all our hits down at the bottom.”

Carrying the load

Through 52⁄3 innings, Quintero was the only Astros player to get a hit off Rockies starter Jhoulys Chacin (3-5).

Actually, he got three — and they proved to be big ones.

Quintero followed his left-field line-hugging RBI double in the second inning — one that gave the Astros a 1-0 lead — with a solo home run to open the fifth, which put the Astros back on top 3-2.

Quintero’s third hit — a two-out single to shallow left in the sixth — proved big as it loaded the bases for Manzella, and the rookie drove in Lee and Hunter Pence with a single to extend the lead to 5-2.

Quintero (3-for-4) and Manzella (1-for-2) were the only Astros to register hits. Lee and Pence had walked.

“I had that one hit that knocked in the two runs, there, but it was (Quintero’s) day,” Manzella said. “He’s been swinging the ball really well the past few weeks (.341 over the past 11 games).”

So has Manzella to start the 10-game road trip. He went 5-for-13 (.385) with four RBIs at Coors Field.

Victory for Oswalt

En route to his first win since May 26 at Milwaukee, Oswalt enjoyed complete control of his fastball and was dominant for much of the game to improve to 4-8.

He retired the first seven batters before walking Clint Barmes in the third inning.

By then he enjoyed a 2-0 lead courtesy of an RBI double by Quintero and sacrifice fly Manzella in the second inning.

“It was nice to get that run support early,” Oswalt said. “It allows you the freedom to try a few different things on the mound.

“After they tied it, ‘Q’ came back out and made the momentum come back all the way. It was a good team win.”